1. Field of the Invention
The present invention is related to an air valve structure for an alternately aerated three-pipe style air bed. And especially to an air valve structure for an air bed having three sets of mutually separated elongate air bladders which can be alternately aerated, discharged or can be all aerated.
2. Description of the Prior Art
A conventional air bed is generally provided with two sets of elongate air bladders. The air bladders are operated like this: the air bladders are both aerated, or the air bladders of odd number are aerated while the air bladders of even number are discharged, or the airbladders of odd number are discharged while the air bladders of even number are aerated. However, the conventional air bed only provided with two sets of elongate air bladders does not meet the practical requirement in consideration of the contact areas of the body of a patient with the air bed. In view of this, an air bed provided with three sets of mutually separated elongate air bladders capable of alternate aeration and discharging is requisite to reduce the distances between every two air bladders being aerated and to more effectively change contact areas of the body of a patient with the air bed to lower the chance of getting decubitus.